Whether because of disease or injury, soft tissue may become detached from bone. A surgeon can use a variety of anchors to reattach soft tissue to bone. Generally, one or more anchors are inserted into bone and the detached tissue is reattached to the bone either by the anchor itself or by one or more sutures coupled to the anchor. Great demands are placed on the anchor. When inserting the anchor into bone, the anchor must have structural strength (e.g., axial and/or torsional strength) to withstand the force/stress of inserting the anchor into the bone. This is especially true when the anchor is inserted into bone without a hole drilled into the bone, a so called “no-hole-prep” approach. Once installed, the anchor must have high fixation strength to resist being pulled out, for example, by the surgeon tensioning the suture.
One anchor design uses wings, which project outwardly, for securing the anchor into bone. Flexibility of the wings is important to achieving high fixation strength. When the anchor is inserted, the wings fold inwardly or comply with the hard outer cortical layer of the bone. Once the anchor is inserted, the wings hold outwardly to flexibly capture to the soft inner cancellous layer of the bone. Making a winged-anchor out of one biocompatible material that is both structurally strong and flexible is challenging. Current state-of-the-art biocompatible materials that are structurally strong, such as carbon fiber reinforced polyether ether ketone (CF PEEK) are stiff and lack sufficient flexibility for achieving high fixation strength in a winged-anchor.